There is a continuing effort to develop improved hydrogenation catalysts which can be used to stabilize lubricating oils. U.S. Pat. No. 4,325,805, granted on Apr. 20, 1982, summarizes advances resulting from recent efforts. According to that patent, the oxidative stability of catalytically dewaxed hydrocrackates was greatly improved by hydrogenation in the presence of a nickel-tin hydrogenation catalyst.
Like many state-of-the-art catalysts, the catalysts described in U.S. Pat. No. 4,325,805 are activated prior to use by reducing the oxidation state of the nickel component. Typically, the reduction was carried out by raising the catalyst to a relatively high temperature, on the order of 700.degree. F. to 800.degree. F. in the presence of hydrogen. However, if these temperatures are reached too rapidly the catalyst can sinter and consequently deactivate.
Accordingly, it is the principle object of the present invention to provide an improved catalyst which is more easily activated than similar conventional catalysts, and yet retains high catalytic activity when used in hydrofinishing processes to stabilize hydrocracked lubricating oils.